Add machines to a cluster

You add one declared machine at a time. Describe the new machine, build the install stick again, and boot the machine from it. This procedure makes no changes to the running machines.

1. Describe the new machine

Add a manifest file to your deployment directory, with the manifests that liken new wrote. Copy an existing machine’s file and change the name, the addresses, and the storage for the new hardware. The comments in the file explain each field.

2. If the new machine is a leader

If the new machine will run a control plane, add its name to spec.leaders in two places:

• On the live cluster, with kubectl edit cluster. The machines read this document, and each machine gets its role from it.
• In your mycluster/cluster.yaml. The file applies only to a new cluster. But if you keep it correct, a new build gives the cluster that you run.

Make the live edit before you install the machine. Keep an odd number of leaders, so that the datastore can always make a majority.

3. Rebuild the install stick

A change to the deployment layer needs new install media. Use the release that your fleet runs. kubectl get clusters shows it in the VERSION column. Pack the layer and the stick again with liken layer and liken stick:

./liken layer mycluster mycluster/identity mycluster/deployment.cpio
./liken stick channel/<version> mycluster/deployment.cpio mycluster/install.img

Check the device name before the next command. The command overwrites the device.

sudo dd if=mycluster/install.img of=/dev/YOUR-STICK bs=4M oflag=direct status=progress

4. Boot the new machine from the stick

The stick’s menu now lists the new machine, with an install as <name> entry and a wipe and reinstall as <name> entry. If you do not know this hardware, boot liken hardware report first. It writes hardware-report.yaml to the stick, so you can correct the machine’s disks, interfaces, and drivers before you install. Install a cluster describes the report and the held console messages fully.

Select install as <name>. The machine installs itself and holds the console:

liken: installed to slot A; remove the stick, then press Enter to power off; the next power-on boots from the disk.

Remove the stick, then press Enter. The machine powers off. Power it on again, and it boots from its own disk.

5. Watch it join

kubectl get machines

The new machine appears, then it becomes Ready. It also appears in kubectl get nodes. The rows of the other machines do not change.